eMedicine Specialties > Sports Medicine > Lower Limb

Iliotibial Band Syndrome

Author: Jerold M Stirling, MD, Chairman of Pediatrics, Professor of Pediatrics and Orthopedics, Loyola University Medical Center
Coauthor(s): Pietro M Tonino, MD, Director and Associate Professor of Sports Medicine, Department of Orthopedic Surgery and Rehabilitation, Loyola University Chicago, Stritch School of Medicine; Consulting Staff, Loyola University Medical Center; Timothy D Marsho, DO, Staff Physician, Department of Pediatrics, Loyola University Medical Center
Contributor Information and Disclosures

Updated: Jan 4, 2008

Introduction

Background

Iliotibial band (ITB) syndrome (ITBS) is the most common cause of lateral knee pain among athletes.^1,2,3,4,5,6 ITBS develops as a result of inflammation of the bursa surrounding the ITB and usually affects athletes who are involved in sports that require continuous running or repetitive knee flexion and extension.^{1,2,3,7,8,9,10} This condition is, therefore, most common in long-distance runners and cyclists. ITBS may also be observed in athletes who participate in volleyball, tennis, soccer, skiing, weight lifting, and aerobics.

For excellent patient education resources, visit eMedicine's Foot, Ankle, Knee, and Hip Center, Arthritis Center, and Osteoporosis and Bone Health Center. Also, see eMedicine's patient education articles Knee Pain Overview, Knee Injury, Tendinitis, and Running.

See also the following on eMedicine:
Iliotibial Band Friction Syndrome [in the Orthopedic Surgery section]
Iliotibial Band Syndrome [in the Physical Medicine and Rehabilitation section]

See also the following on Medscape:
CME Medical Interventions Effectively Treat Overuse Injuries in Adult Endurance Athletes
Deep Transverse Friction Massage for Treating Tendinitis

Frequency

United States

ITBS is the most common cause of lateral knee pain in runners. Although few studies are available regarding the incidence of ITBS in athletes, some studies cite this condition with an incidence as high as 12% of all running-related injuries.¹¹  Several studies of US Marine Corps recruits undergoing basic training determined the incidence of ITBS among this group to vary from 5.3 to 22.2%.

International

Data are not available regarding the international incidence of ITBS.

Functional Anatomy

The ITB is the condensation of fascia formed by the tensor fascia lata and the gluteus medius and minimus muscles. The ITB is a wide, flat structure that originates at the iliac crest and inserts at the Gerdy tubercle on the lateral aspect of the proximal tibia. This band serves as a ligament between the lateral femoral condyle and the lateral tibia to stabilize the knee. The ITB assists in the following 4 movements of the lower extremity:

• Abducts the hip
• Contributes to internal rotation of the hip when the hip is flexed to 30°
• Assists with knee extension when the knee is in less than 30° of flexion
• Assists with knee flexion when the knee is in greater than 30° of flexion

The ITB is not attached to bone as it courses between the Gerdy tubercle and the lateral femoral epicondyle. This lack of attachment allows it to move anteriorly and posteriorly with knee flexion and extension. Some authors hypothesize that this movement may cause the ITB to rub against the lateral femoral condyle, causing inflammation. Other investigators hypothesize that injury of the ITB results from compression of the band against a layer of innervated fat between the ITB and epicondyle. Furthermore, a potential deep space is located under the ITB as it crosses the lateral femoral epicondyle and travels to the Gerdy tubercle. This bursa may become inflamed and cause a clicking sensation as the knee flexes and extends. The inflamed bursa may add another component to ITB tendinitis.
 
See also the following on eMedicine:
Bursitis [in the Emergency Medicine section]
Bursitis [in the Orthopedic Surgery section]
Tendonitis

Sport-Specific Biomechanics

In runners, the posterior edge of the ITB impinges against the lateral epicondyle of the femur just after foot strike in the gait cycle.^7,8 This friction occurs at or slightly below 30 º of knee flexion.^2,3,7 Downhill running and running at slower speeds may exacerbate ITBS as the knee tends to be less flexed at foot strike.

In cyclists, the ITB is pulled anteriorly on the pedaling downstroke and posteriorly on the upstroke. The ITB is predisposed to friction, irritation, and microtrauma during this repetitive movement because its posterior fibers adhere closely to the lateral femoral epicondyle.

Clinical

History

The usual clinical history describes lateral knee pain:

• Pain with activity
  • Typically, the patient with ITBS presents with an insidious onset of lateral knee pain that is present during running.
  • Early in the course of the injury, the pain usually resolves after running.
  • If the athlete continues to run, the pain may progress to being present during walking and between training sessions.
• Pain localized over the lateral femoral epicondyle
  • The athlete is able to localize the lateral knee pain to approximately 2 cm above the lateral joint line.
  • Untreated, the pain may eventually radiate to the distal tibia, calf, and up to the lateral thigh.
• Pain while climbing stairs or running downhill
  • Pain is commonly experienced when the athlete climbs stairs or runs downhill.
  • Pain may develop with any activity that places the knee in a weight-bearing position at approximately 30º of knee flexion.
• Pain at rest
  • Pain at rest is usually associated with severe tendinitis, an associated lateral meniscus tear, an associated lateral femoral condyle bruise, or a cartilage injury.

• Any time there is pain at rest but no history of acute or repetitive trauma, the practitioner should ask questions to rule out neoplasm, infection, or inflammatory arthropathy.

See also the following on eMedicine:
Knee Injury, Soft Tissue 
Knee, Meniscal Tears (MRI) [in the Radiology section]
Meniscus Injuries [in the Sports Medicine section]
Meniscal Injury [in the Physical Medicine and Rehabilitation section]

Physical

Physical examination findings in patients with ITBS may include the following:

• Abnormal gait: The athlete may walk with the affected knee extended because this gait pattern avoids motion in which the tendon rubs on the lateral femoral epicondyle.
• Point tenderness is noted upon palpation of the lateral femoral epicondyle, as well as with palpation of a site 2-4 cm above the lateral joint line and at the Gerdy tubercle. Oftentimes, the patient indicates pain with the use of the palm of the entire hand.
• Reproducible pain: Pain may be elicited with knee flexion to 30° when varus stress is applied to the knee.
• The Ober test is used to assess the flexibility of the ITB. To perform this test, the examiner instructs the athlete to lie on the uninjured side. The examiner stabilizes the athlete's pelvis with one hand while controlling the affected limb with the other hand. The examiner abducts and extends the affected hip toward the table. Once the hip is abducted, the examiner adducts the hip. If the hip resists adduction, it is a result of tightness of the ITB (see Image 1).

Causes

• Runners
  • The posterior edge of the ITB impinges against the lateral epicondyle of the femur just after foot strike in the gait cycle. This friction occurs at or slightly below 30 º of knee flexion. Downhill running and running at slower speeds may exacerbate ITBS because the knee tends to be less flexed at foot strike.
  • Running on hard surfaces and banked surfaces: The injured leg is often the downside leg on a banked or crowned road.
  • Worn out or improper running shoes
  • Lower limb and foot misalignment such as valgus or varus alignment of the leg or leg-length discrepancy
• Cyclists
  • In cycling, the ITB is pulled anteriorly on the pedaling downstroke and posteriorly on the upstroke. The ITB is predisposed to friction, irritation, and microtrauma during this repetitive movement because its posterior fibers adhere closely to the lateral femoral epicondyle.
  • Cyclists with an external tibia rotation greater than 20 º: Stress is created on the ITB if the athlete's cycling shoe is placed in a straight-ahead position or the toe is in a cleat position.
  • Cyclists with varus knee alignment or active pronation place a greater stretch on the distal ITB when they ride with internally rotated cleats.
  • Poorly fitted bicycle saddle: A high-riding saddle causes the cyclist to extend the knee more than 150 º. This exaggerated knee extension causes the distal ITB to abrade across the lateral femoral condyle. Bicycle saddles that are positioned too far back cause the cyclist to reach for the pedal, with a resultant stretch to the ITB.
• All athletes
  • Improper warm-up and stretching
  • Increasing the quality and quantity of training sessions too quickly
  • Lower limb and foot misalignment such as valgus or varus alignment of the leg or leg-length discrepancy
  • Worn out or improper athletic shoes
  • On occasion, a contusion to the knee may precipitate ITBS.

• Search for CME/CE on This Topic »

• Iliotibial Band Syndrome (Physical Medicine and Rehabilitation)
• Iliotibial Band Friction Syndrome (Orthopedic Surgery)
• Tendonitis (Emergency Medicine)